Others say...

"Fun while it lasted"
I don't have much to add, but I do wish to remind you that, if you're sqeamish, you may not like this game. Once you get past a few shocking images, it is really just very nice to look at. I was pleased by the almost 360-degree viewpoint, smooth character movement and very realistic surroundings. The 1920's Paris setting lends itself well to rich details, especially in the wallpaper and furnishings.
I also liked the spookiness and the period music, but--as other reviewers have mentioned, it's sometimes frustrating to have to listen to dialogue over and over (I prefer to turn off the subtitles, by the way) and I often found myself returning to the same location many times just to see if I had missed anything.
Along the way, there are, of course, puzzles one must solve. I had help and once I unlocked each location, there was always an interesting little movie to watch. One annoying little thing was that I had trouble saving it, so I figured out that it was best make twos saves at the same point, just to be safe.
The ending--the epilogue, really--made me say, "Wha...?" but I still had fun and it didn't take me weeks to get through like 7th Guest or 11th Hour.

"Good game"
This is a good game, but there has to be some middle line for these adventure games. Some have no character interaction and are all puzzles, and some have to much dialog which is the problem with this one. Dialog changes as you go, so you can have different endings which is a neat idea. And the characters are interesting, but you spend to much time talking.
Other than that it is a good game.

"A Little Disappointing"
I played this game right after Syberia which I think was part of the problem. Syberia I and II are so visually stimulating and flows into an enjoyable plot. Post Mortem was too dark, the graphics were not nearly as good as expected and the characters actions became annoying (arm and hand movements when they spoke). Granted it was creepy and kept me curious enough to keep going.I did, however, enjoy the ending.

"Not so great"
This game may have suffered b/c of its budget. It was very short (Which is characteristics of games from developer Microid), and there are many bugs in the game. The game designers try to incorporate non-linear gaming by allowing multiple paths to go through a certain part of the game. However, as a result, you may get stuck at a part of the game without any possibility to advance but to reload a saved game. Sometimes dialogues will be about things that you haven't discovered yet, so that leaves you confused about the story.

The story was underdeveloped. The main character has psychic abilities, but that wasn't utilized too much in the game. Also, the inventory system is pretty bad. You have to scroll through a horizontal bar to choose an item; that gets annoying when you have like 50 items with you. The graphics also didn't look too great on my computer, but then again my video card was outdated, so that could be why.

"post mortem"
Save your money, (even if it goes on sale) this is the worst game I have ever played. If you want to play a fun game play Longest Journey or Syberia or Dark Fall, Post Mortem is the most boring game ever and the music was lousy, interaction was awful, and the characters have no personality. The puzzles are almost non-existant. Sorry, but I wasted my money so save yours.